Best practices for making high integrity lightweight metal castings - molten metal composition and cleanliness control

To make high integrity lightweight metal castings, best practices are required in various stages of casting and heat treatment processes, including liquid metal composition and quality control, casting and gating/riser system design, and process optimization. This paper presents best practices for liquid metal processing and quality assurance of molten metal in both melting and mold filling. Best practices for other aspects of lightweight metal casting will be published separately

Multivariate Supply Model of Small-Scale Irrigation and Water Conservancy Facilities in China Rural Area

The supply of small-scale irrigation and water conservancy facilities has received wide attentions from the academic circles. In China,the deficiency of providing public goods in rural areas have hindered rural and agricultural development, and restricted the modernization of governance in China to some extent.It is urgent to seek a way to solve these issues.Through history and comparative analysis, this paper first divides the supply model of small-scale irrigation and water conservancy facilities into three categories on the basis of existing research, which are state centralized supply, self-financing farmers and multivariate supply; Secondly, we focus on launching a further research and refinement on multivariate supply model which is under way in current practice, and we proposed that four main actors and four stages constitute the multivariate supply model. Four main actors are government, farmers, NGOs and private sector and four stages refer to investment, construction, management and maintenance and usage; Thirdly , through the investigation and research of Z county in Anhui Province, we found that the small-scale irrigation and water conservancy in Z county is in general accord with the multivariate supply model. Specific performance is in the aspects of increasingly diverse investment channels, increasingly flexible construction ways and constant innovation of management and maintenance models, these characteristics verify the rationality and feasibility of multivariate supply model. Finally, we point out the matters needed to pay special attention when using multivariate supply model to effectively solve the problem in the process of supply of small-scale irrigation and water conservancy facilities in Rural China. Keywords: Small-scale Irrigation And Water Conservancy, Public Governance, Multi-participation, Supply Mode

A novel recombinant pseudorabies virus expressing parvovirus VP2 gene: Immunogenicity and protective efficacy in swine

<p>Abstract</p> <p>Background</p> <p>Porcine parvovirus (PPV) VP2 gene has been successfully expressed in many expression systems resulting in self-assembly of virus-like particles (VLPs) with similar morphology to the native capsid. Here, a pseudorabies virus (PRV) system was adopted to express the PPV VP2 gene.</p> <p>Methods</p> <p>A recombinant PRV SA215/VP2 was obtained by homologous recombination between the vector PRV viral DNA and a transfer plasmid. Then recombinant virus was purified with plaque purification, and its identity confirmed by PCR amplification, Western blot and indirect immunofluorescence (IFA) analyses. Electronic microscopy of PRV SA215/VP2 confirmed self-assembly of both pseudorabies virus and VLPs from VP2 protein.</p> <p>Results</p> <p>Immunization of piglets with recombinant virus elicited PRV-specific and PPV-specific humoral immune responses and provided complete protection against a lethal dose of PRV challenges. Gilts immunized with recombinant viruses induced PPV-specific antibodies, and significantly reduced the mortality rate of (1 of 28) following virulent PPV challenge compared with the control (7 of 31). Furthermore, PPV virus DNA was not detected in the fetuses of recombinant virus immunized gilts.</p> <p>Conclusions</p> <p>In this study, a recombinant PRV SA215/VP2 virus expressing PPV VP2 protein was constructed using PRV SA215 vector. The safety, immunogenicity, and protective efficacy of the recombinant virus were demonstrated in piglets and primiparous gilts. This recombinant PRV SA215/VP2 represents a suitable candidate for the development of a bivalent vaccine against both PRV and PPV infection.</p

The value of DCE- MRI of the breast as a diagnostic tool in assessing amorphous calcifications in screening mammography

PurposeTo evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging in differentiating benign and malignant amorphous calcifications.MethodsThis study included 193 female patients with 197 suspicious amorphous calcifications detected on screening mammography. The patients’ demographics, clinical follow-up, imaging, and pathology outcomes were reviewed, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DCE-MRI were calculated.ResultsOf 197 lesions (193 patients) included in the study, 50 (25.4%) were histologically proved to be malignant. DCE-MRI based on breast imaging report and diagnosis system (BI-RADS) had a sensitivity of 94.4%, specificity of 85.7%, PPV of 69.1%, and NPV of 97.7% for the detection of malignant amorphous calcifications. Notably, diagnosis solely based on the presence or absence of DCE-MRI enhancement showed the same sensitivity but significantly decreased specificity (44.8%, p &lt; 0.001) and PPV (44.8%, p &lt; 0.001). In patients with a minimal or mild degree of background parenchymal enhancement (BPE), the sensitivity, specificity, PPV, and NPV increased to 100%, 90.6%, 78.6%, and 100%, respectively. However, in patients with a moderate degree of BPE, MRI resulted in three false negatives of ductal carcinoma in situ (DCIS). Overall, the addition of DCE-MRI detected all invasive lesions and could decrease unnecessary biopsy by 65.5%.ConclusionDCE-MRI based on BI-RADS has the potential to improve the diagnosis of suspicious amorphous calcifications and avoid unnecessary biopsy, especially for those with low-degree BPE

Final Amalgamation Processes of the Southern Altaids: Insights from the Triassic Houhongquan Ophiolitic Mélange in the Beishan Orogen (NW China)

AbstractThe Permian–Triassic tectonic setting is still controversial in the southern Altaids. The Beishan orogen is an ideal region to address the final tectonic of the Altaids. These systematic mapping, geochemistry, and geochronology studies on the Houhongquan ophiolitic mélange in the south Beishan are conducted to address this issue. New mapping reveals that the Houhongquan ophiolitic mélange consists of blocks of gabbro, basalt, chert, granite, and strongly deformed and cleaved sandstone in the southern Beishan. The studies reveal that the mafic fragments are relics of normal-mid-ocean ridge (N-MOR) and suprasubduction zone (SSZ) types of oceanic lithosphere. The four sandstone matrix samples yield the maximum depositional ages of 222±5 Ma, 233.8±2.3 Ma, 263.4±2.5 Ma, and 263.5±2.8 Ma, respectively, indicating that the youngest sandstones were tectonic emplaced in the Houhongquan ophiolitic mélange after ca. 222 Ma. The sandstone matrices display two types of age spectra. Early Permian sandstones have a single Devonian to Early Permian peak age patterns, indicating the existence of an independent Permian intraoceanic arc. In contrast, Late Triassic sandstones have multiple peaks with some Precambrian zircons, suggesting that they were sourced from a continental arc. Accordingly, we consider that the Houhongquan ophiolitic mélange tectonic was emplaced in the intraoceanic island arc during the Middle Permian and docked to a continental margin arc during the Late Triassic. Thus, we argue that the terminal amalgamation timing of the southern Altaids was probably during ca. 222-217 Ma

The molecular diversity of transcriptional factor TfoX is a determinant in natural transformation in Glaesserella parasuis

Natural transformation is a mechanism by which a particular bacterial species takes up foreign DNA and integrates it into its genome. The swine pathogen Glaesserella parasuis (G. parasuis) is a naturally transformable bacterium. The regulation of competence, however, is not fully understood. In this study, the natural transformability of 99 strains was investigated. Only 44% of the strains were transformable under laboratory conditions. Through a high-resolution melting curve and phylogenetic analysis, we found that genetic differences in the core regulator of natural transformation, the tfoX gene, leads to two distinct natural transformation phenotypes. In the absence of the tfoX gene, the highly transformable strain SC1401 lost its natural transformability. In addition, when the SC1401 tfoX gene was replaced by the tfoX of SH0165, which has no natural transformability, competence was also lost. These results suggest that TfoX is a core regulator of natural transformation in G. parasuis, and that differences in tfoX can be used as a molecular indicator of natural transformability. Transcriptomic and proteomic analyses of the SC1401 wildtype strain, and a tfoX gene deletion strain showed that differential gene expression and protein synthesis is mainly centered on pathways related to glucose metabolism. The results suggest that tfoX may mediate natural transformation by regulating the metabolism of carbon sources. Our study provides evidence that tfoX plays an important role in the natural transformation of G. parasuis